Program: GN-2021A-FT-211

There is overwhelming evidence from spectroscopic, polarimetric and photometric variability as well as from imaging of stellar ejecta and hydrodynamic modelling, that hot stellar winds are non-stationary and inhomogeneous. In other words, hot-star winds are "clumpy". This has huge implications on many predictions for massive-star evolution and on diagnostics of the large impact massive stars have on their environment through their mass loss. Unfortunately, there are currently no existing wind models that can comprehensively describe the clump distribution. Consequently, clumping is mostly included in models as a free variable, which limits our ability to quantify fundamental parameters such as the mass loss rate accurately. We recently discovered a relation between a star’s wind clumping and its effective temperature, which, if confirmed, has the potential to offer a new observational constraints for wind models. This proposal is to use GMOS to strengthen and confirm this relation by measuring the amplitude of the spectral line profile variations due to clumping in the wind of WR 143, a Wolf-Rayet star with an effective temperature in a range that was poorly covered in our previous sample. Depending on the results, we may propose for more time later to cover more stars in the same temperature range.